Rainbow Electronics AT75C220 - Manual (Page 99)

AT75C220
99
TC: Timer/Counter
The AT75C220 features a timer/counter block which
includes three identical 16-bit timer/counter channels. Each
channel can be independently programmed to perform a
wide range of functions including frequency measurement,
event counting, interval measurement, pulse generation,
delay timing and pulse-width modulation.
Each timer/counter channel has three external clock inputs,
five internal clock inputs, and two multi-purpose input/out-
put signals that can be configured by the user. Each chan-
nel drives an internal interrupt signal that can be pro-
grammed to generate processor interrupts via the AIC.
The timer/counter block has two global registers which act
upon all three TC channels. The Block Control Register
allows the three channels to be started simultaneously with
the same instruction. The Block Mode Register defines the
external clock inputs for each timer/counter channel, allow-
ing them to be chained.
Figure 22. Timer/Counter Block Diagram
Timer/Counter
Channel 0
Timer/Counter
Channel 1
Timer/Counter
Channel 2
SYNC
Parallel I/O
Controller
TC1XC1S
TC0XC0S
TC2XC2S
INT
INT
INT
TIOA0
TIOA1
TIOA2
TIOB0
TIOB1
TIOB2
XC0
XC1
XC2
XC0
XC1
XC2
XC0
XC1
XC2
TCLK0
TCLK1
TCLK2
TCLK0
TCLK1
TCLK2
TCLK0
TCLK1
TCLK2
TIOA1
TIOA2
TIOA0
TIOA2
TIOA0
TIOA1
Advanced
Interrupt
Controller
TCLK0
TCLK1
TCLK2
TIOA0
TIOB0
TIOA1
TIOB1
TIOA2
TIOB2
Timer/Counter Block
TIOA
TIOB
TIOA
TIOB
TIOA
TIOB
SYNC
SYNC
ACLK/2
ACLK/8
ACLK/32
ACLK/128
ACLK/1024